Long distance dispersal shaped patterns of human genetic diversity in Eurasia

Alves, Isabel; Arenas Busto, Miguel; Currat, Mathias; Sramkova Hanulova, Anna; Martins Conde e Sousa, Vitor; Ray, Nicolas; Excoffier, Laurent (2016). Long distance dispersal shaped patterns of human genetic diversity in Eurasia. Molecular Biology and Evolution, 33(4), pp. 946-958. Oxford University Press 10.1093/molbev/msv332

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Most previous attempts at reconstructing the past history of human populations did not explicitly take geography into account, or considered very simple scenarios of migration and ignored environmental information. However, it is likely that the Last Glacial Maximum (LGM) affected the demography and the range of many species, including our own. Moreover, long-distance dispersal (LDD) may have been an important component of human migrations, allowing fast colonization of new territories and preserving high levels of genetic diversity. Here, we use a high-quality microsatellite dataset genotyped in 22 populations to estimate the posterior probabilities of several scenarios for the settlement of the Old World by modern humans. We considered models ranging from a simple spatial expansion to others including LDD and a LGM-induced range contraction, as well as Neolithic demographic expansions. We find that scenarios with LDD are much better supported by data than models without LDD. Nevertheless, we show evidence that LDD events to empty habitats were strongly prevented during the settlement of Eurasia. This unexpected absence of LDD ahead of the colonization wave front could have been caused by an Allee effect, either due to intrinsic causes such as an inbreeding depression built during the expansion, or to extrinsic causes such as direct competition with archaic humans. Overall, our results suggest only a relatively limited effect of the LGM-contraction on current patterns of human diversity. This is in clear contrast with the major role of LDD migrations, which have potentially contributed to the intermingled genetic structure of Eurasian populations.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE) > Population Genetics
08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE)

UniBE Contributor:

Alves, Isabel; Arenas Busto, Miguel; Sramkova Hanulova, Anna; Martins Conde e Sousa, Vitor and Excoffier, Laurent

Subjects:

500 Science > 570 Life sciences; biology

ISSN:

0737-4038

Publisher:

Oxford University Press

Language:

English

Submitter:

Isabelle Duperret

Date Deposited:

27 Jan 2016 16:28

Last Modified:

26 Jun 2016 02:09

Publisher DOI:

10.1093/molbev/msv332

BORIS DOI:

10.7892/boris.74783

URI:

https://boris.unibe.ch/id/eprint/74783

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